Low-noise inverter drives for elevators

Mitsubishi Electric has incorporated integrated-gate bipolar transistors (IGBTs) to develop a high-frequency inverter drive that is much quieter than conventional drive units resulting in a much smaller unit since it does not require electronic and acoustic noise control measures. Use of IGBTs, operating at higher frequencies than bipolar transistor modules, has had a major impact on elevator design. Measures previously required to control acoustic and electromagnetic noise can be largely eliminated by using a higher PMW carrier frequency, leading to dramatic size and cost reductions in the final product.